Failure analysis of laser diodes using transmission electron microscopy

We carried out failure analysis of InGaAsP/InP buried hetero-structure laser diodes using transmission electron microscopy. Climb motion of dislocation half loops in a regrowth layer caused rapid degradation. Generations of dislocation micro-loops at regrown interfaces gradually reduced output power for long periods of operation. In a suddenly failed laser chip, we observed a melt mark elongated from a crack crossing an active layer.